The present invention relates to an apparatus for heating water. More particularly, the present invention relates to a portable apparatus for heating water that may also be self-contained. In certain embodiments, the present invention may used to provide heated water for showers, cleaning, food preparation, and the like.
Heated water is expected by many to be readily available under circumstances that may range from simple convenience to practical necessity. With usage varying from bathing to hot food, there is a demand for heated water over a broad range of temperatures and volumes. Consequently, water heaters and piping are installed as permanent fixtures for water delivery in homes, offices, and industrial settings. Faucets supplying heated water may be installed in fixed locations at anticipated points of use.
For some applications, a portable system for heating water may be required. Soldiers in the field may establish remote, temporary camps needing a portable water supply with heating capability. Requirements for military readiness and mobility may dictate that equipment should not be bulky, cumbersome, or difficult to unpack and setup. Similarly, campers may plan extended outdoor events in areas with water but limited or no access to heated water. Pet owners may wish to bathe an animal outside of the home but may not have an outdoor faucet supplying heated water.
Furthermore, permanent fixtures for the delivery of heated water remain unavailable in parts of the world. The infrastructure necessary for water delivery from a central location to individual homes and businesses may not be available. Elsewhere, a readily available water supply may exist but without fixtures for heating or an energy source to provide the heat.
Thus, an apparatus capable of heating water that is portable and that may be self-contained is desirable. Self-contained, as used with the present invention, means an apparatus capable of heating the water without requiring connection to an external or remote power source or remote fuel source. An apparatus that can also rapidly heat water without requiring storage in insulated tanks or containers would be an added benefit for portability.
Various devices for heating water exist. As the following examples demonstrate, the portability and degree of self-containment varies. U.S. Pat. No. 5,524,820, issued to Regan, discloses a device described as a portable water heater unit for field use. The device includes a housing containing a water heater and uses a heated water storage tank. An external supply of a flammable liquid fuel provides an energy source for heating. A pump and various controls are powered by an external power supplyxe2x80x94i.e. the device must be plugged into a generator, external battery, or receptacle for operation. Accordingly, the portability of this device is delimited by the requirement that external equipment must be used in the disclosed embodiments.
U.S. Pat. No. 4,947,025, issued to Alston et al., discloses a portable electric water heater. The device contains a coiled water conducting tube and a rheostat for varying the amount of current supplied to the electric heating element. The power supply for the electric heating element is external to the device and serves to limit its portability.
U.S. Pat. No. 4,552,125 issued to Borodulin et al, discloses a portable solar water heater. The device includes a table containing solar collector panels for heating water when exposed to solar radiation. By definition, this device is limited to use during time periods when solar energy is available.
Numerous references disclose outdoor showering equipment, but each assumes either a separate device for supplying heated water, or an external power source for heating the water. U.S. Pat. No. 5,774,908, issued to Hall, discloses an outdoor shower with a chamber for holding water to be heated by solar energy. U.S. Pat. No. 5,920,927, issued to Thomas, discloses a combined portable shower and toilet assembly without a means for heating the water within the device. U.S. Pat. No. 5,911,520, issued to Kenney, discloses a portable shower apparatus with a vessel for storing water that can also be pressurized. Water of the desired temperature is placed into the vessel without an internal means for heating the water. U.S. Pat. No. 5,852,836, issued to Montrose, discloses a portable shower with water that is dispensed from a container within the apparatus. Water is placed into the container at the desired temperature without an internal means for heating.
Accordingly, a need exists for a portable apparatus that can provide for heating water. An apparatus that is portable and also self-contained is also needed. Specifically, there is a need for an apparatus that can heat water over a wide range of volumes and temperatures while minimizing the weight and space of the apparatus. The apparatus should also have an embodiment that can provide heated water without requiring connection to an external fuel supply or power source that is not equipped with the apparatus.
The present invention is directed to water heater that is portable and has a minimum of weight and requires minimal space. In specific embodiments, the present invention is also self-contained in that connection to an external power or fuel source is not required for heating water. The storage of heated water within tanks that add weight and consume space is also not required. The present invention also provides an apparatus that may be used to heat water for showering, cleaning, food preparation, and other applications where heated water is desired. The apparatus is not limited to heating water, and may be used by those skilled in the art with the teachings disclosed herein to heat other aqueous fluids that are non-flammable and that are not otherwise sensitive to the application of heat.
Specific embodiments of the present invention may be used in applications where a minimum of space is available. Accordingly, embodiments of the present invention may be installed into boats, campers, or other transportation vessels to provide heated water for showers, sinks, and the like. These embodiments may connect to an existing fuel source or power supply at the point of installation.
Furthermore, certain embodiments of the present invention may also be self-contained and of a size that can be easily transported by a single person. Thus, embodiments of the present invention may be used by soldiers, campers, sportsmen, or others desiring a portable and self-contained apparatus for heating water. For these embodiments, a fuel source or energy source may be provided with the apparatus so that connection to an external fuel supply or electrical power source is not necessary. A handle may also be provided in these embodiments for transporting the apparatus.
In one particular embodiment, the present invention includes a housing with a water inlet conduit, through which water to be heated may enter the housing. A pump is located within the housing. The pump has a supply section and a discharge section. The supply section of the pump is in fluid communication with the water inlet conduit. A battery is also located within the housing for providing power to operate the pump.
A heat exchanger is located within the housing that has an inlet section and an outlet section. The inlet section is in fluid communication with the discharge section of the pump. The heat exchanger preferably includes a conically-shaped interior coil. The conically-shaped interior coil is constructed of conduit and has a first end and a second end. The diameter of the conically-shaped interior coil decreases along the coil axis from the first end to the second end of the coil. The heat exchanger also includes a cap that is located proximate to the second end of the conically-shaped interior coil. The heat exchanger has an exterior coil constructed of conduit that is in fluid communication with the conically-shaped interior coil and the outlet section of the heat exchanger. A water outlet conduit is provided that is in fluid communication with the outlet section of the heat exchanger. Heated water may exit the housing of the water heater through the water outlet conduit.
The water heater includes a fuel inlet section, releasably connectable to a fuel source, through which fuel may be supplied to the water heater. A gaseous fuel control system is provided for controlling the flow of fuel from the fuel inlet section. A burner section, located in the housing, is provided for generating heat from fuel supplied to the water heater. The gaseous fuel control system connects the fuel inlet section to the burner section.
The gaseous fuel control system includes a valve that is located subsequent in flow to the fuel inlet section. An orifice, having an effective diameter in the range of about 0.010 to about 0.030 inch, is in communication with the valve. A port, also having an effective diameter in the range of about 0.010 to about 0.030 inch, is also in communication with the valve. During operation, fuel flows from the fuel inlet section and through the valve, then through the first orifice, and then through the port.
Accordingly, by way of example only and using the embodiment above described, to provide heated water from the portable water heater, the fuel inlet section is connected to a fuel supply through the resealable connection. The water inlet conduit is connected to or immersed into a water supply. If the water is not already pressurized, the pump is powered by connecting it to the battery. After obtaining flow of the water from the water outlet conduit, the burner section is ignited and begins to create heat through combustion of the fuel.
Unheated water enters the housing through the water inlet conduit and then flows to the supply section of the pump. When the pump is powered, the pump causes water to flow through the discharge section of the pump and into the inlet section of the heat exchanger. As the water travels through the coils of the heat exchanger, the temperature of the water increases from heat generated by the burner section. Heated water flows through the outlet section of the heat exchanger and is then released from the housing through the water outlet conduit. The valve may be adjusted to vary temperature of the water to enable one to obtain heated water at a desired temperature.
This description of an embodiment of the present invention is provided by way of example only. Various other embodiments exist and may be practiced using the teachings disclosed herein. By way of example only, the water outlet conduit may be connected to a shower head so that the apparatus may be used to heat water for bathing. Alternatively, in another embodiment, the present invention may include only a burner section, gaseous fuel control system, and fuel inlet section. Such an embodiment might be installed within the heated water system of a boat or camper to provide a heat source requiring only a minimum of space. In addition, the pump, switch, battery and fuel source may also be included, but without the housing, so as to provide a water heater that is self-contained but occupying a minimum of space.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention.